Devices for respiratory protection have accelerated in recent decades. The health care and industrial work place industries have a need for practical, economical and effective devices for delivering clean or filtered respirable air as a means of protection from environmental contaminants. Agriculture also is in need of protection as it applies to ambient work place contaminants. Allergy sufferers and the more severe environmentally sensitive individuals could greatly benefit from low-cost convenient respiratory devices that do not add any additional respiratory stress. Currently, the largest percentage of the respiratory protection market is represented by the disposable and half mask cartridge negative pressure respirator. However, in recent years, new studies have demonstrated that negative pressure respirators offer limited protection as exposure limits for many substances and particulates are lowered by various approval agencies such as the Occupational Safety and Health Administration (OSHA) as well as the Center for disease Control (CDC). In response, many occupational professionals are selecting the positive pressure Powered Air Purifying Respirator.
Negative pressure respirators can be inherently uncomfortable, leading to less user wear time. A respirator that is not worn or is not worn correctly has a protection factor of zero. Negative pressure respirators increase respiratory stress, and must be fit tested. A fit check must be performed each time the respirator is donned. Facial hair eliminates the use of a negative pressure respirator. Disposable and half mask cartridge respirators have the lowest protection factor rating compared to all other types of respirators including the Powered Air Purifying Respirator.
Conversely, Powered Air Purifying Respirators (PAPRs) are not dependent upon the wearer's breathing capacity and avoid many of the noted implementation problems. PAPRs use small battery operated motor and fan assemblies to produce filtered, respirable air by drawing ambient air through a filter element. The respirable air is then distributed through various distribution strategies to the user's facial breathing zone, namely the nose and mouth area. A positive pressure of 5-12 cu. ft./min. is maintained in typical systems which displaces any contaminated air in the breathing zone of a wearer.
Since PAPRs are positive pressure devices, they eliminate the potential for pulmonary stress in a user. PAPR systems can be constructed to be simply, easily attachable devices delivering respirable air to a user. Since no special seals need be created on the user, PAPRs avoid any problems due to improper donning or inadequate fit problems. PAPR filters typically have larger surface areas than disposable filters and last longer than the disposable sort. Also, disposable respirators are typically discarded immediately after use, increasing the cost over the longer lasting, reusable, PAPR filters. PAPR devices offer broader protection in industry because they can be used for substance filtration in addition to simple particulate removal. Because of the forgoing, integration of PAPRs into an employee protection system is more easily accomplished than their disposable counterparts.
In terms of emergency respiratory apparatus, PAPRs may be used as a companion device under certain conditions. Escape type respirators are simple and small, often utilizing a belt mounted compressed air cylinder. A full face mask or other type of head piece may be used, but generally a clear plastic hood is utilized. During an emergency, such as a release of a toxic substance, escape respirators are donned, sometimes necessitating the doffing of a non-emergency type respirator. Risk inherent in escape type respirators include the inability to don the emergency respirator quickly enough. Exhausting the emergency air supply (usually 5-15 minutes of air) before reaching a safe area is of critical importance. Light weight PAPRs such as a shield or visor could make a combination escape apparatus and a workplace PAPR companion that would utilize the air purifying features of the PAPR during normal work shifts, and provide escape features for emergency situations. The combination air delivery device and escape apparatus would eliminate doffing and donning procedures. At the end of useful service life of the escape apparatus, the PAPR could once again be used to continue the orderly escape using filter media design optimized for escape situations.
In firefighting, a Self Contained Breathing Apparatus (SCBA) could be used during the initial stages of structural firefighting, after which time an air delivery system could be attached to the firefighter's helmet to aid in respiratory protection from contaminates associated with clean-up, ventilation and inspection.
Even with the inherent advantages of PAPRs, current PAPR systems are expensive and cumbersome when compared with disposable and half mask cartridge respirators. Most systems are integrated into safety helmets during manufacturing, adding unavoidable cost. Other types of PAPRs utilize head covers, such as the above mentioned helmet, as well as hoods, shrouds, and completely fabricated helmeted welding systems. These systems provide positive air flow that often include the head neck and face areas of the individual user. In these cases, filtered air may be contaminated by the hair and skin of the user prior to respiration.
Typically the bulky helmeted loose fitting devices have few aesthetic features and little retail acceptance. Innovations of the head piece assembly, as it applies to the PAPR, is seriously lacking in both the industrial work place and in the health care industry.
Another drawback with current systems is that they are relatively expensive to implement. Helmets or hoods of various sizes and shapes must be inventoried by the organization using the PAPRS, thereby necessitating the purchase of relatively expensive pre-manufactured PAPRS. These PAPRs then replace other types of relatively low cost and user accepted protective gear, such as, but not limited to, the standard construction helmet or unrespirated miner's helmet.
Other than current industrial PAPRs, low-cost, low-complexity, comfortable PAPRs for casual or retail health use are non-existent. Also, there have been few innovations in current PAPR inlet covers. Conversely, personal protection devices such as safety eye wear, head protection, and hearing protection have made major strides in design and function. Light weight, practical and cosmetically appealing appliances are now the norm in these fields. However, one only needs to see the bulky, helmeted, hood, and loose fitting shrouds that are typical of the PAPR headpiece to appreciate the fact that aesthetics and retail acceptance have heretofore not been considerations. These drawbacks are a result of the over complexity of current PAPR systems and lack of industry innovation.
Absent from the arsenal of PAPRs presently found in the market place are respiratory systems that may be incorporated into existing conventional personal safety products such as helmets, safety eyeware, face shields, caps, headbands, welding shields, all presently used on a wide scale as the result of product innovation and design. The environmentally sensitive, many who are house bound, have few retail products that consider the need for aestically but inconspicuous designs that offer the advantages of a PAPR, yet may be worn in public places.
Moreover, the health care industry has need to replace the half masks currently used. Half-masks are uncomfortable to wear over extended periods and do not provide the broad range protection needed in today's health care environments. The health care industry is currently attempting to implement PAPR type devices, but has been slow to adopt them due to problems associated with intimidating appearance of the apparatuses, cost of disposable headpieces, and general incompatibility with the typical dress normally associated with a health care worker.
In conjunction with the discussed industry needs and retail market opportunities, legislation is taking form that will promote the utilization of PAPRs. New OSHA federal regulations will mandate new protections for "bio-aerosols" such as MDR tuberculosis, and new NIOSH regulations proscribe certain disposable respirators unless specially approved HEPA filter media are incorporated. Furthermore, industry continues to debate the validity of protection factors established by NIOSH, ANSI, and other committees, as they apply to negative pressure, half-mask and disposable respirator systems. This confusion over the validity of protection factors tends to diminish the desire to implement half-mask and disposable respirators in a system-wide fashion.
Therefore, there is a strong need for a PAPR that can be economically incorporated into preexisting, conventional protective gear, such as safety helmets or protective eye wear. There is also a strong need for a simple and economical, retail oriented PAPR which can be adapted for application specific uses, and for casual use of PAPRs.